Texans defense has turned into one of the league's best

Having lost their starting quarterback and their highest-paid defensive player in the middle of the season, the Houston Texans are arguably the unlikeliest team left in the NFL's final eight.

But the Ravens say they aren't surprised by the 11-6 Texans, nor was offensive coordinator Cam Cameron by the touchdown that propelled the AFC South champions into the divisional round.

Last Saturday, in the final minute of the first half, rookie defensive end J.J. Watt slipped a block and plucked a line-drive pass from Cincinnati Bengals quarterback Andy Dalton out of the air with his left hand, then returned it 29 yards for a tie-breaking, morale-crushing score.

Houston took a 17-10 lead and the momentum into halftime. And as Cameron watched from his seat inside Reliant Stadium, the Texans eventually eliminated the Bengals, 31-10.

"What a play," Cameron said Thursday. "If he'd have batted that down, that would have been a heck of a play. To not only catch it [but] then run it for a touchdown, that changed that game."

The reconstructed Texans defense, which ranks among the NFL's elite in many major statistics, has helped keep the team's title hopes intact after quarterback Matt Schaub and sack specialist Mario Williams suffered season-ending injuries. And like the Bengals did a week ago, the 12-4 Ravens will have their hands full Sunday when the Texans return to M&T Bank Stadium.

To think, a year ago, their 30th-ranked defense was the main reason the Texans finished 6-10.

With a new defensive coordinator (Wade Phillips, who a season ago was the head coach of the Dallas Cowboys), a new scheme and an infusion of talent in the offseason, the Texans' defense has experienced one of the most significant single-season swings in modern NFL history.

In 2010, the Texans surrendered 376.9 yards of offense per game. In 2011, the second-ranked Texans defense allowed 285.7 — a difference of 91.2 yards, which is the biggest improvement in total defense since 1998 and the third-most since the 1970 AFL-NFL merger.

Opposing offenses scored 17.4 points per game against the Texans this season — 9.3 fewer than in 2010.

"They've always had the players there," said Ravens safety Bernard Pollard, who played for the Texans in 2009 and 2010. "Wade has brought his system in and everybody is so comfortable."

Williams had five sacks in five games before tearing a pectoral muscle. But his loss has been buoyed by the play of third-year linebacker Connor Barwin, who leads the Texans with 11.5 sacks a year after missing the entire regular season with an ankle injury.

Barwin is one of six starters on the Houston defense and one of 15 of the 25 defenders on their roster who have spent three seasons or fewer in the NFL. Only one defensive starter, defensive end Antonio Smith, is 30 years old. And the Texans are starting two rookies: Watt and Brooks Reed, who are the first pair of rookie teammates to each record five or more sacks since 1997.

Cameron said the Ravens' defensive coaches liked Watt — the first of five defensive players the Texans selected with their first five picks in the 2011 draft — and other Texans as draft prospects.

"They've been building their roster now for three, four, five years," Ravens coach John Harbaugh said. "They've been on the brink every year. ... And now, they've done it. So, we're not surprised. We've played them a lot. They are very talented, well-coached and very formidable."

That is especially true of Houston's front seven, which produced four sacks in the wild card win against Cincinnati and harassed Dalton, a rookie, into three interceptions.

The Texans employ a 3-4 front that, like the Ravens' defense, can switch to a 4-3 if one of their outside linebackers sticks his hand in the dirt. They move around their versatile linebackers — Barwin, Reed, DeMeco Ryans and leading tackler and team MVP Brian Cushing — to confuse offenses, and their starting defensive ends, Watt and Smith, combined to rack up a dozen sacks.

The Texans finished sixth in the NFL with 44 sacks, and they allowed opposing quarterbacks to complete just 51.9 percent of their passes. And when they generated turnovers — they ranked 12th with 27 takeaways — they were cashed in for touchdowns 56 percent of the time.

"They're high-motor guys," Ravens center Matt Birk said. "You can see that they have gotten better, which is to be expected from young guys. Their styles of play fit their type of defense. They fly around, get out on the edges, work moves and they can win one-on-one matchups."

The men in Houston's secondary are no slouches, either. The Texans, who signed cornerback Johnathan Joseph and safety Danieal Manning in the offseason, ranked third in pass defense.

With Joseph trailing him all afternoon, Ravens wide receiver Anquan Boldin caught eight passes for 132 yards in Baltimore's 29-14 win Oct. 16. It wasn't Joseph's day, but on Friday Ravens quarterback Joe Flacco admitted that Joseph has "gotten me quite a handful of times" over the years. Joseph, who made his first Pro Bowl in 2011, spent his first five seasons with the Bengals.

Manning picked off a pair of passes in the regular season and was fourth on the team with 59 tackles.

"They've been a big, big difference in the confidence of our defense and how well we've been able to grow kind of quickly this year without the offseason," Texans head coach Gary Kubiak said.

From their nose tackle to their safeties on the back end, the rebuilt Texans defense appears to have few flaws, especially after you scan the stat sheet. Putting up points Sunday won't be easy.

"This is a team that has had everybody's attention the whole year. Houston is not sneaking up on anybody," Cameron said. "We know the quality of the team that is coming in here to play."